Zinc finger (ZF) and transcription activator-like effector (TALE) based technologies are been allowing the tailored design of “artificial” DNA-binding proteins targeted to specific and unique DNA genomic sequences. Coupling DNA binding proteins to effectors domains enables the constitution of DNA binding factors for genomic directed transcriptional modulation or targeted genomic editing. We have demonstrated that pairing a ZF DNA binding protein to the transcriptional repressor Kruppel-associated box enables in vivo, the transcriptional repression of one of the most abundantly expressed gene in mammals, the human rhodopsin gene (RHO). We propose to generate RHO DNA binding silencers (“AlleleChoker”), which inactivate RHO either by transcriptional repression or targeted genome modification, irrespectively to wild-type or mutated alleles (mutational-independent approach), and combine RHO endogenous silencing to RHO replacement (silencing-replacement strategy). With this strategy in principle a single bimodal bio-therapeutic will enable the correction of any photoreceptor disease associated with RHO mutation. Adeno-associated viral (AAV) vector-based delivery will be used for photoreceptors gene transfer. Specifically our objectives are: 1) Construction of transcriptional repressors and nucleases for RHO silencing. Characterization and comparison of RHO silencing mediated by transcriptional repressors (ZFR/ TALER) or nucleases (ZFN/ TALEN) to generate genomic directed inactivation by non-homologous end-joining (NHEJ), and refer these results to RNA interference (RNAi) targeted to RHO; 2) RHO silencing in photoreceptors. to determine genome-wide DNA binding specificity of silencers, chromatin modifications and expression profile on human retinal explants; 3) Tuning silencing and replacement. To determine the impact of gene silencing-replacement strategy on disease progression in animal models of autosomal dominant retinitis pigmentosa (adRP) associated to RHO mutations